Outside cutter



Sept! 13, 1949. w. c. ERWIN 2,481,831

OUTSIDE CUTTER Filed April `24, 1948 INVENTOR WELDON C. ERWIN ATTORNEY Patented Sept. 13, 1949 UNITED STATES PATENT OFFICE OUTSIDE CUTTER Weldon o. Erwm, south Gate, Calif.

Application April Z4, 1948, Serial No. 23,100

8 Claims. (Cl. 164-0.7)

This invention relates to a device for cutting off drill pipe, tubing or casing in wells, and relates in particular to an outside pipe cutter of simple form which is operable in spaces of reduced dimension, wherein cuttingdevices of form now commonly employed cannot be operated.

Quite often the pipe to be cut off in a well by means of an outside cutter is so large in relation to the well bore or casing in which the pipe is lodged thatthe usual or ordinary types of outside cutters cannot be used, because the wall thickness of these cutters is greater than the annular space around the pipe to be cut in which the cutter must be moved and operated. It is an object of the invention to provide an outside cutter for pipe or tubing in wells having operative parts carried by a hollow cylindric body which is of reduced thickness, thereby providing a tool having a maximum inside diameter and a minimum outside diameter, so that the tool may be operated in an annular space of such size that it will n ot'receiveA ordinary cut-oi tools.

It is an object of the invention to provide a pipe cutting device of -this character, having its cooperating parts so correlated and combined that the results set forth in the foregoing may be achieved. Y Y

A further objectof the invention is to provide a simple outsidecutting device for pipe or tubing in a well which does not utilize springs for or in conjunction with the forcing of the cutter blades inwardly into engagement with the pipe to be cut, but utilizes* force derived from an upward scribed a preferred embodiment of the invention for the purpose of making a complete and clear disclosure of the same without limiting the scope of the invention which is set forth in the appended claims.

Referring to the drawings, which are for illusrative purposes only.

Fig. l is a sectional view through a preferred embodiment of the invention and a portion of the pipe therein.

Fig. 2 is a partly sectioned elevational view of Fig. l, taken from the position indicated by the line 2--2 of Fig. 1.

Fig. 3 is a sectional view taken as indicated by the line 3-3 of Fig. 1.

Fig. '4 is a fragmentary sectional view, taken as indicated by the line [-44 of Fig. 2.

As shown in the drawings, the device includes a body Iii, comprising a relatively thin cylindric Iwall II which is adapted to be connected to the lower end of a string Aof tubing 9 in any desired manner, s'o that this cylindric wall Il may be lowered down around a pipe I2 whichris to be cut. Herein the term pipe designates a pipe member comprising a plurality of pipe sections joined together'in the manners customary to oil well drilling practicesfOrdinarily the pipe sectionsV are connected by threaded collars, tool joints and sleeves.- As shown in Fig. l, the inpull on the pipe string which supports the cutting device for feeding of the cutters radially in-V wardly during the cutting operation.

It is an object of the invention to provide an outside cutting device of this character, wherein all of the operating parts, with the exception of windows formed in the cylindric body of the de- Y vice and simple means for effecting movement of the blad-es into cuttingl engagement with the pipe at a selected time.

Further objects and advantages of the invention will be brought out in the following part of the specification, wherein I have in detail deternally threaded collar |3vof a pipe section I4 may be integrallyformed on the end ofthe pipe section, the threaded'endof a consecutive pipe section I5 being screwed thereinto.

ln the cylindric wall I I, a number of chambers IS are formed, in which cutter-'blades Il and cutter actuating members' I8 are located. These chambers I6 are open to the interior of the cylindric Wall I I so that the cutter blades l1 may be swung inwardly to the kdotted line positions thereof indicated at Ilv in Fig. 1,'and so that dogs I9may swing inwardly into the internal space of the cylindricjwall Il. However, in the preferred practice ofthe'invention, the chambers I6 are also open tothe exterior of the cylindric wall `II so as `to constitute` vertically elongated windows in the'cylindricwall II.

vThese chambers I6, or windows, as they will be now called, are dened by sidewalls v2l), upper end walls 2|, and lower stepped end walls 22. The lower end walls 22 have therein notches 23 to receive the lower ends of the cutter blades I'l and tangentially disposedV pins 24 are passed through the lower ends vof the blades I1 and the adjacent wallsof the notches 23, so as to hingedly connect the lower ends of the cutters I1 to the body or cylindric wall II of the device. At least the lower portions of the side walls 20 of the windows I6 are undercut or relieved adjacent the inner face 25 of the cylindric wall II, these undercuts being indicated by the numeral 26 in Figs. 2, 3, and 4 of the drawings.

The cutter actuating members I8 may be -conveniently referred to as blocks. They are rectangular in outlineyrand are arched in accordance with the curvature fof the. cyl-Lndric wall II', Likewise, the thickness of these blocks I8 corresponds to the thickness of the cylindric wall II. At their upper ends, the blocks I8 have portions 2'5 of reduced thickness for connection vto an annular member or ring 28 which is vertically slidable in an annular recess 29 in the cylindric wall II. This recess 29 may be conveniently formed by counterboring the upper portion of the cylindric wall II, thereby reducing the thickness of the upper portion 30 ofthe cylindric wall I I' and leaving therein an annular-,recess in which the ring 28 is vertically slidable.. The thickness of the ring 1,8. is. such that it. will not project inwardly beyond .the inner face 2.5 of the lower portion of the cylindric wall II. The upper portions of theV cutter feed blocks I8 are connected to the ring 28 as by screws 31;, so that the ring 28 will connect the blocks I8 im. simultalltous or unitary movement. The lower ends of the blocks I 3 are provided with downwardly directed proiections 32 having sloping faces 33 to engage the contiguous faces at: the; upper ends of the blades Il. Also, the blocks IB have along the lower portionsv ci their Side walls; enlargements or ilanges 3d which rest in the undercuts 26., are vertically slidable in. these undercutsvv 2li and prevent radially outward moyen-lent vof the Vlower portions of the Vlolocks I8 relatively to the eyli-ndric wall lil. The upper ends of the blocks I8 are held in the windows I6 by the ring 2,3... Releasable means are provided fcrpreventing relative downward movement of the blocks I8 in the windows I6, until such downward movement. is required for the cutting operation which vill.v be hereinafter described. The releasable resti!.raining or holding means operative between thecylindric wall II and the blocks I8 comprise Shearable pins 35 which pass through cooperating openings. in. the ring 2;3, andthe adjacent portion of the cylindri-c wall II.

Each cutter feed block I8 has. therein an aperture asin whiff/h a dog L9 iS. pivotally mounted on a horizontal pin- 3'?. 'I'lfiis pin 31 is disposed near the lower Wall f the aperture-35, so that the dog may be swung .from the inwardly projecting position thereof show-,n vill .fllll lines. in Eig. 1 upwardly and'outwardlyinto retracted position in the aperture 3S `as shown dotted lines I9' in Fig. 1. Coil springs areprevided for urging the dogs I9 into the inwardly projecting positions thereof These springs 38, are disposed in notches 39.7in the outer end portions or the dogs I9. The inner eri-ds VMi ofthe dogs, i9 are rounded as shown in Figi for engagement with portions of the pipe I During the time the cutting dev-ice is being lowered inter the. well, the cutter blades I1 ocoupyV positions within. the lower portions of the windowsld. At this time. there are no elements, with the exception 0,5 the dogs l'9, projecting outwar-illy from the. outer surface of the cylindric wall ll or inwardly the surface 25 thereof.. Accordingly, the annular space re. quired. around the-pipe. i2. .to receive the cutting device seed acabe materially thicker than the maximum wall thickness of the wall I I. During the lowering of the device around the pipe I2,

the springs 38 urge the dogs I9 into the full line rpositions thereof. Whenever a projection on the pipe I2, such as a tool joint, collar, or sleeve, is met by the inner portions of the inwardly projecting dogs I9 duringtheir downward movement, the dogs merely swing upwardly and out` wardly towarvdthedotted line positions] 9 thereof and rideover the obstructions Whenthecutting device reaches the position at'which the pipe I2 is to be cut oi, the device is lifted so that the inwardly projecting portions of the dogs I9 will be lifted into engagement with a downwardly faced shoulder` 44, suchas provided at the lower of the blades Il inwardlyasgthe.. hinge pinsj'ZIl,Y

Eig; 1, move upwardly `from the .fullline positions to the dotted line positionsthereoi'in Fig. 1. During this upward movement, the `cylindric wall I I will be. rotated Ytreuer direction, Y thereby causing the points of the blades I'I to travel'circularl-y as they move inwardly', to cut a groove in the pipe I2 andsever the same.. During this rotation or the cylindricwalli I', the. dogs I9 are carried through `a circular path of movement, and slide around the shoulder Mot the. collar I3. ".Io facilitate ease of operation and to'elimi/nate as much as possible damage to `the tool er breakage oi the knives, I have devised a. method-of movingthe operating; string ofi pipe upwardly,

other than bythe regular hoist .er drawworks usually provided. with a rotary drilling rig.v This hoisting equipment employs a. vcable..which has one end thereof wound er1 the spool of the drawworks, the cable. then'being threaded through-the sheaves of the crown and traveling blocks, and the remaining end beingv then-'attached to an anchor in one cerner of the derriclr..` Tothis remaining or dead end of the cableL I connect a'y chain hoist or anhydraul-ic ram so as to gradually pull down on the dead end.. and thereby slowly and smoothly lift the trayeling block which s connected to the upper end ofthe operating string of pipe or tubingwhich carries at its lower end the cutting device herein disclosed. By thismeans, the cutting device can be moved upwardly at a controlled rate, without any jerking action, feeding the knives. inwardly to cut ofi the eine in a smooth and steady manner.

i I, claim as my invention.: Y

l.. In an outside loi-pe cutting device adapted to .n

be lowered around a pipe having downwardly faced. shoulders .or .ecllarslthe combinationfof: a cylindric wall havingal pluralityof chambers open to the inter-.lor .foi-fthe oylindric wall; a. cutter blade. hinged the lower part. oi; each of said chambers so as to be swingable inwardly to engage aulne; a cutter feed blocksupeorted in the uriner Y part of each oisaid chambers .Se as to bei-.noved up. and down with relationl Yto :the cutter blade.

in the chamber, said feed andsaid blades having cooperating.. faces whereby downward movement or said. 'blocks produce g inward movement of the-cutter blades tecut the einer al? `annular member connecting said blocks together so that they willmove in unison; pipe engaging dogs respectively supported by said blocks so as to move fromA inwardly projecting positions upwardly and outwardly to positions wherein they will clear the collars on the pipe as the device is moved downwardly around the pipe, said dogs being adapted to engage shoulders on the pipe when the device 'is moved upwardly, thereby holding the blocks stationary while upward movement of the cylindric wall carries said blades upwardly with relation to said blocks, whereby the blades will be swung inwardly against the pipe to be cut; and releasable means cooperating between the blocks and the cylindric wall to restrain them from relative movement while the device is being lowered.

2. In an outside pipe cutting device adapted to be lowered around a pipe having downwardly faced shoulders or collars, the combination of: a cylindric wall having a plurality of chambers open to the interior of the cylindric wall and having an annular recess therein communicating with said chambers; a cutter blade hinged in the lower vpartof each of said chambers so as tovbe swingable inwardly'tol engage a pipe; a cutter feed block supported in the upper part of each of said chambers so as to be moved up and down with relation to the cutter blade in the chamber, Said feed blocks and said blades having cooperating faces whereby downward movement of said blocks will produce inward movement of the cutter blades to cut the pipe; an annular member vertically slidable in said recess and connecting said blocks together so that they will move in unison; pipe i engaging dogs respectively supported by said blocks so as to move from inwardly projecting positions upwardly and outwardly to positions wherein they will clear the collars on the pipe as the device is moved downwardly around the pipe, said dogs being adapted to engage shoulders on the pipe when the device Vis moved upwardly, thereby holding the blocks stationary while upward movement of the cylindric wall carries said blades upwardly with relation to said blocks, whereby the blades will be swung inwardly against the pipe to be cut; and vreleasable means cooperating between the blocks and the cylindric wall to restrain them fromrelative movement while the device is being lowered,

3. In an outside pipecutting device adapted to be lowered around a pipey having downwardly faced shoulders or collars, the combination of: a cylindric wall having ay plurality of chambers open to the interior of the cylindric wall; a cutter blade hinged in the lower part of each of said chambers so as to be swingable inwardly to engage a pipe; a cutter feed block supported in the upper part of eachrof said chambers so as to be moved up and down with relation to the cutter blade in thechamber, each Aof said blocks having a recess therein and said feed blocks and said blades having Vcooperating faces whereby downward movement of said blocks wl produce inward movementwof the cutter. blades to cut the pipe; an annular member connecting said blocks together so that they will move in unison; pipe engaging dogs respectively hinged in said recesses of said blocks so as to be swingable from inwardly projecting pipe engaging positions upwardly and outwardly to retracted positions in the recesses of said blocks wherein they will clear the collars on the pipe as the device is moved downwardly around the pipe, said dogs being adapted to engage shoulders on the pipe when the device is moved upwardly, thereby holding the blocks sta'- tionary while upward movement of the cylindric wall carries said blades upwardly with relation to said blocks, whereby the blades will be swung inwardly against the pipe to be cut; springs urging said dogs into said inwardly projecting positions; and releasable means cooperating between the blocks and the cylindric wall to restrain them from relative movement while the device is being lowered.

4. In an outside pipe cutting device adapted to be lowered around a pipe having downwardly faced shoulders or collars, the combination of a cylindric wall having a plurality of chambers open to the interior of the cylindric wall and having an annular recess therein communicating with said chambers; a cutter blade hinged in the lower part of each of said chambers so as to be swingable inwardly to engage a pipe; a cutter feed block supported in the upper part of each of said chambers so as to be moved up and down with relation to the cutter blade in the chamber, each of said blocks having a recess therein and said feed blocks and said blades having cooperating faces whereby downward movement of said blocks will produce inward movement of the cutter blades to cut the pipe; an annular member vertically slidable in said recess and connecting said blocks together so that they will move in unison; pipe engaging dogs respectively hinged in said recesses of said blocks so as to be swingable from inwardly projecting pipe engaging positions upwardly and outwardly to retracted positions in the recesses of said blocks wherein they will clear the collars on the pipe as the device is moved downwardly around the pipe, said dogs being adapted to engage shoulders on the pipe when the device is moved upwardly, thereby holding the blocks Stationary while upward movement of the cylindric wall carries said blades upwardly with relation to said blocks, whereby the blades will be Vswung inwardly against the pipe to be cut; springs urging said dogs into said inwardly projecting positions; and releasable means cooperating between the blocks and the -cylindric wall to restrain them from relative movement while the device is being lowered.

5. In an outside pipe cutting device adapt-ed to be lowered around a pipe having downwardly faced shoulders or collars, the combination of: a cylindric wall having a plurality of vertically elongated windows therein and having `an lannular recess communicating with the upper portions of the windows, at least the lower portions of the side walls of said windows bein-g undercut; cutters hing-ed respectively in the lower por-` tions of said vwindows so as to be swingable in Awardly from positions within said windows to pipe cutting positions; cutter feed blocksV vertically slidable in said windows, at least the lower portions of said blocks having lateral extensions to engage the undercut portions of the side walls of Vsaid windows, thereby preventing radially `outward movement of said blocks relatively to the .said device is moved upwardly and holdsaid iblocks stationary While upward movement of said cylindric wall carries said .blades upwardly with relation to the blocks; lan annular wal'l in said recess of sai-d cylindric wall, connecting the upper portions of said blocks; 4and releasable means operative between the blocks and the cylindric wall to hold the 'blocks in fixed relation to said cylindric wall during downward movement of the device.

6. In an outside pipe cutting device adapted to be lowered around av pipe having downwardly faced shoulders or collars, the combination of.: a cylindric wall having a plurality of vertically elongated windows therein and havingan annuzlar recess in the internal face thereof communieating with the upper portions of the windows, at least the lower portions of the side walls of said windows being undercut; cutters hinged respectively in the lower portions of said windows so as `to be swingable inwardly from positions Within said windows to pipe cutting positions; cutter feed blocks vertically slidable in said windows, atleast the lower portions of said blocks having lateral extensions to engage the undercut portions of the side walls of said windows, thereby preventing radially outward movement of said blocks relatively to the cylindric wall, said blocks and said blades having cooperating faces whereby downward movement of said blocks in said windows will swing said cutter blades inwardly against the pipe; pipe engaging dogs respectively supported by said blocks so as to move from inwardly projecting pipel engaging positions upwardly and outwardly into positions wherein they will clear collars on the pipe as the device is lowered around the pipe, said dogs being adapted to engage the pipe when said device is moved upwardly and hold said blocks stationary while upward movement of said cylindric wall carries said blades upwardly with relation to the blocks; an annular wall disposed and vertically slidable in said recess of said cylindric wall, connecting the upper portions of said blocks; and releasable means operative between the blocks and the cylindric wall to hold the blocks in fixed relation to said cylindric wall during downward movement of the device.

7. In an outside-pipe cutting device adapted to be vlowered around a pipe having downwardly faced shoulders or collars, the combination of: a cylindric wall having a plurality of vertically elongated windows therein and having an annular recess communicating with the upper portions of the windows, at least the lower portions of the side walls f said windows being undercut; cutters hinged respectively in the lower portions of said windows so as to be swingable inwardly from positions within said windows to pipe cutting positions; cutter feed blocks vertically slidable in said windows, at least the lower portions of said blocks having lateral extensions to engage the undercut portions of the side walls of said windows, thereby preventing radially voutward movement of said blocks relatively t0 the cylindric wall, each of said blocks having an aperture therein and said blocks and said blades hav- 'ing cooperating faces whereby downward movement of said blocks in said Windows will swing said cutter blades inwardly against the pipe; pipe engaging dogs respectively hinged in said aperl tures of said blocks so as to be swingable from inwardly projecting pipe engaging positions upwardly and outwardly into said apertures wherein they will clear collars on the pipe as the device is lowered around the pipe, said dogs being adapted to engage the pipe when said device is moved upwardly and hold said blocks stationary Y while upward movement of said cylindric wall carries said blades upwardly with relation to the blocks; springs urging said dogs into said inwardly projecting positions; an annular wall in said recess of said cylindric wall, connecting the upper portions of said blocks; and releasable means `operative between the blocks and the cylindric wall to hold the blocks -in Xed relation to said cylindric wall during downward movement of the device. Y 'Y i l 8. In' an outside pipe cutting device adapted to lbe lowered around a pipe lhavingv downwardly faced shoulders or collars, the combination of:

a cylindric wall having a plurality of vertically elongated windows therein and havingan annular recess in the internal face thereof communicating'with the upper portions of the windows, at least the lower portions of the side walls of said windows being undercut; cutters hinged respectively in the lower portions of said windows so as to be swingable inwardly ,from positions within said windows to pipe cutting positions;

cutter-feed blocks vertically slidable in said win-V dows, at least the lower portions of said blocks having lateral extensions to engage the undercut portions of the side Walls of said windows, thereby preventing radially outward movement of said Y into said apertures wherein they will clear collars on the pipe as the device islowered around the pipe, said dogs being adapted to engage the pipe when said device is moved upwardly and hold said blocks stationary while upward movement of said cylindric wall carries saidblades upwardly with relation to the blocks; springs urging said dogs into said inwardly projecting positions; an annular wall disposed and vertically slidable in said recess of said cylindric wall, lconnecting the upper portions of said blocks; and releasable means operative between the blocks and the cylindric wall to hold the blocks inXed relation to said cylindric wall during downward movementY of the device.

WELDON C. ERWIN.

No references cited. 

